U.S. patent application number 16/950547 was filed with the patent office on 2022-05-19 for method of manufacturing multi-layer electrode for a capacitive pressure sensor and multi-layer electrodes formed therefrom.
This patent application is currently assigned to Ford Global Technologies, LLC. The applicant listed for this patent is Ford Global Technologies, LLC. Invention is credited to Pietro Buttolo, Jim Robert Chascsa, Paul Kenneth Dellock, Richard Gall, Stuart C. Salter.
Application Number | 20220155107 16/950547 |
Document ID | / |
Family ID | |
Filed Date | 2022-05-19 |
United States Patent
Application |
20220155107 |
Kind Code |
A1 |
Salter; Stuart C. ; et
al. |
May 19, 2022 |
METHOD OF MANUFACTURING MULTI-LAYER ELECTRODE FOR A CAPACITIVE
PRESSURE SENSOR AND MULTI-LAYER ELECTRODES FORMED THEREFROM
Abstract
A multi-layer electrode of a capacitive pressure sensor is
manufactured by roll to roll printing a conductive layer onto a
polymer layer and forming a mutual capacitance sensor layer of the
capacitive pressure sensor, co-extruding a conductive polymer layer
and a foam dielectric layer and forming a coextruded layer of the
capacitive pressure sensor, and pressure rolling the mutual
capacitance sensor layer and the coextruded layer together and
forming the multi-layer electrode. The conductive polymer layer
includes between about 2 wt. % to about 15 wt. % graphene and
between about 0.01 wt. % and 5 wt. % of the carbon nanotubes. Also,
the conductive polymer layer has a flexural modulus equal to or
greater than 5,000 MPa and an electrical resistivity less than or
equal to 10 Ohm/mm.sup.3, and the polymer layer and/or the
conductive polymer layer is formed from recycled polyethylene
terephthalate.
Inventors: |
Salter; Stuart C.; (White
Lake, MI) ; Buttolo; Pietro; (Dearborn Heights,
MI) ; Dellock; Paul Kenneth; (Northville, MI)
; Gall; Richard; (Ann Arbor, MI) ; Chascsa; Jim
Robert; (Farmington Hills, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ford Global Technologies, LLC |
Dearborn |
MI |
US |
|
|
Assignee: |
Ford Global Technologies,
LLC
Dearborn
MI
|
Appl. No.: |
16/950547 |
Filed: |
November 17, 2020 |
International
Class: |
G01D 5/24 20060101
G01D005/24; G01L 9/00 20060101 G01L009/00; G01L 9/12 20060101
G01L009/12; C08L 75/08 20060101 C08L075/08 |
Claims
1. A multi-layer electrode of a capacitive pressure sensor
manufactured according to a method comprising: roll to roll
printing a conductive layer onto a polymer layer and forming an XY
layer of the capacitive pressure sensor; co-extruding a conductive
polymer layer and a foam dielectric layer and forming coextruded
layers of the capacitive pressure sensor; and pressure rolling the
XY layer and the coextruded layers together and forming the
multi-layer electrode.
2. The multi-layer electrode according to claim 1, wherein the roll
to roll printing comprises rotogravure printing conductive ink onto
the polymer layer and forming the conductive layer.
3. The multi-layer electrode according to claim 2, wherein the
conductive ink layer has a thickness between about 10 .mu.m to
about 100 .mu.m.
4. The multi-layer electrode according to claim 2, wherein the
conductive ink layer comprises at least one or silver, graphene,
carbon, and indium tin oxide.
5. The multi-layer electrode according to claim 1, wherein the
conductive polymer layer comprises polyethylene terephthalate
(PET).
6. The multi-layer electrode according to claim 5, wherein the PET
is recycled PET.
7. The multi-layer electrode according to claim 1, wherein the
conductive polymer layer comprises a filler.
8. The multi-layer electrode according to claim 7, wherein the
filler comprises graphene and carbon nanostructures.
9. The multi-layer electrode according to claim 8, wherein the
carbon nanostructures comprise carbon nanotubes.
10. The multi-layer electrode according to claim 9, wherein the
conductive polymer layer comprises between about 2 wt. % to about
15 wt. % of the graphene and between about 0.01 wt. % and 5 wt. %
of the carbon nanotubes.
11. The multi-layer electrode according to claim 10, wherein the
conductive polymer layer has a flexural modulus equal to or greater
than 5,000 MPa.
12. The multi-layer electrode according to claim 10, wherein the
conductive polymer layer has an electrical resistivity less than or
equal to 10 Ohm/mm.sup.3.
13. The multi-layer electrode according to claim 10, wherein the
conductive polymer layer has a flexural modulus equal to or greater
than 5,000 MPa and an electrical resistivity less than or equal to
10 Ohm/mm.sup.3.
14. The multi-layer electrode according to claim 1, wherein the
conductive polymer layer comprises between about 2 wt. % to about
15 wt. % of graphene, between about 0.01 wt. % and 5 wt. % of
carbon nanotubes, a flexural modulus equal to or greater than 5,000
MPa and an electrical resistivity less than or equal to 10
Ohm/mm.sup.3.
15. The multi-layer electrode according to claim 14, wherein the
conductive polymer layer comprises between about 8 wt. % to about
10 wt. % of the graphene and between about 0.01 wt. % and 1 wt. %
of the carbon nanotubes.
16. A multi-layer electrode for a capacitive pressure sensor
manufactured according to a method comprising: roll to roll
rotogravure printing a conductive ink layer onto a polymer layer
and forming an XY layer of the multi-layer electrode; co-extruding
a conductive polymer layer with a foam dielectric layer and forming
coextruded layers of the multi-layer electrode; and pressure
rolling the XY layer and the coextruded layers together and forming
the multi-layer electrode, wherein the dielectric foam layer is in
contact with the conductive ink layer.
17. The multi-layer electrode according to claim 16, wherein the
conductive polymer layer comprises between about 2 wt. % to about
15 wt. % of graphene, between about 0.01 wt. % and 5 wt. % of
carbon nanotubes.
18. The multi-layer electrode according to claim 17, wherein the
conductive polymer layer has a flexural modulus equal to or greater
than 5,000 MPa and an electrical resistivity less than or equal to
10 Ohm/mm.sup.3.
19. A multi-layer electrode for a capacitive pressure sensor
manufactured according to a method comprising: roll to roll
rotogravure printing a conductive ink layer onto a polymer layer
and forming an XY layer of the multi-layer electrode; co-extruding
a conductive polymer layer with a foam dielectric layer and forming
coextruded layers of the multi-layer electrode, wherein the polymer
layer comprises between about 2 wt. % to about 15 wt. % of
graphene, between about 0.01 wt. % and 5 wt. % of carbon nanotubes;
and pressure rolling the XY layer and the coextruded layers
together and forming the multi-layer electrode, wherein the
dielectric foam layer is in contact with the conductive ink
layer.
20. The multi-layer electrode according to claim 19, wherein the
conductive polymer layer has a flexural modulus equal to or greater
than 5,000 MPa and an electrical resistivity less than or equal to
10 Ohm/mm.sup.3.
Description
FIELD
[0001] The present disclosure relates to manufacturing multi-layer
electrodes and particularly to low cost manufacturing multi-layer
electrodes.
BACKGROUND
[0002] The statements in this section merely provide background
information related to the present disclosure and may not
constitute prior art.
[0003] Electrical switches are commonly used to "turn on", "turn
off", and/or regulate functions and operations of machines. For
example, switches for radio control, audio volume control, heating
and/or air conditioning control, cruise control, among others, are
typically included and placed or located on a steering wheel of a
vehicle such that a driver can reach the switches without removing
their hands from the steering wheel. In addition, some, if not
most, of the electronic switches are pressure activated, i.e., are
activated by pressure applied by the driver.
[0004] The present disclosure addresses issues related to pressure
activated switches and other issues related to manufacturing of
pressure activated switches.
SUMMARY
[0005] This section provides a general summary of the disclosure
and is not a comprehensive disclosure of its full scope or all of
its features.
[0006] In one form of the present disclosure, a multi-layer
electrode for a capacitive pressure sensor is manufactured by roll
to roll printing a conductive layer onto a polymer layer and
forming a mutual capacitance sensor layer, co-extruding a
conductive polymer layer and a foam dielectric layer and forming a
coextruded layer, and pressure rolling the mutual capacitance
sensor layer and the coextruded layer together and forming the
multi-layer electrode.
[0007] In some variations, the roll to roll printing is rotogravure
printing of conductive ink onto the polymer layer to form the
conductive layer. Non-limiting examples of the conductive ink
include silver inks, copper inks, carbon nanotube inks,
carbon/graphene inks, and conductive polymer inks, among others.
And in at least one variation, the conductive ink layer has a
thickness between about 5 micrometers (.mu.m) and about 100 .mu.m,
for example, between about 5 .mu.m and about 50 .mu.m, between
about 7.5 .mu.m and about 30 .mu.m, or between about 10 .mu.m and
about 20 .mu.m.
[0008] In some variations, the conductive polymer layer includes
polyethylene terephthalate (PET), and in at least one variation the
PET is recycled PET. For example, the PET is from recycled PET
beverage containers.
[0009] In some variations, the conductive polymer layer includes a
filler. In such variations the filler can be at least one of
graphene and carbon nanostructures such as carbon nanotubes. For
example, in at least one variation the conductive polymer layer
includes between about 2 wt. % to about 15 wt. % graphene and
between about 0.01 wt. % and 5 wt. % carbon nanotubes.
[0010] In some variations, the conductive polymer layer has a
flexural modulus equal to or greater than 5,000 MPa. In the
alternative, or in addition to, the conductive polymer layer has an
electrical resistivity less than or equal to 10 Ohm/mm.sup.3. In at
least one variation, the conductive polymer layer includes between
about 2 wt. % to about 15 wt. % graphene, between about 0.01 wt. %
to about 5 wt. % carbon nanotubes, a flexural modulus equal to or
greater than 5,000 MPa, and an electrical resistivity less than or
equal to 10 Ohm/mm.sup.3. And in some variations, the graphene
content is between about 8 wt. % to about 10 wt. % and the carbon
nanotubes content is between about 0.01 wt. % and 1 wt. %.
[0011] In another form of the present disclosure, a multi-layer
electrode for a capacitive pressure sensor is manufactured by roll
to roll rotogravure printing a conductive ink layer onto a polymer
layer to form a mutual capacitance sensor layer, co-extruding a
conductive polymer layer and a foam dielectric layer form a
coextruded layer, and pressure rolling the mutual capacitance
sensor layer and the coextruded layer together such that the
dielectric foam layer is in contact with the conductive ink layer
to form the multi-layer electrode. In some variations, the
conductive polymer layer includes between about 2 wt. % to about 15
wt. % graphene and between about 0.01 wt. % and 5 wt. % carbon
nanotubes. In the alternative, or in addition to, the conductive
polymer layer has a flexural modulus equal to or greater than 5,000
MPa and an electrical resistivity less than or equal to 10
Ohm/mm.sup.3.
[0012] In still yet another form of the present disclosure, a
multi-layer electrode for a capacitive pressure sensor is
manufactured according to a method that includes roll to roll
rotogravure printing a conductive ink layer onto a polymer layer
and forming a mutual capacitance sensor layer of the multi-layer
electrode, co-extruding a conductive polymer layer and a foam
dielectric layer and forming a coextruded layer of the multi-layer
electrode, and pressure rolling the mutual capacitance sensor layer
and the coextruded layer together and forming the multi-layer
electrode. The conductive polymer layer includes between about 2
wt. % to about 15 wt. % of graphene and between about 0.01 wt. %
and 5 wt. % of carbon nanotubes. Also, the dielectric foam layer is
in contact with the conductive ink layer. In some variations, the
conductive polymer layer has a flexural modulus equal to or greater
than 5,000 MPa and an electrical resistivity less than or equal to
10 Ohm/mm.sup.3.
[0013] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the
description and specific examples are intended for purposes of
illustration only and are not intended to limit the scope of the
present disclosure.
DRAWINGS
[0014] In order that the disclosure may be well understood, there
will now be described various forms thereof, given by way of
example, reference being made to the accompanying drawings, in
which:
[0015] FIG. 1 is side view of a roll to roll printer forming a
mutual capacitance sensor layer of a multi-layer electrode
according to the teachings of the present disclosure;
[0016] FIG. 2 is a top view of the mutual capacitance sensor layer
formed in FIG. 1 with a conductive ink layer printed on a polymer
layer;
[0017] FIG. 3A is a view of section 3A-3A in FIG. 2;
[0018] FIG. 3B is a view of section 3B-3B in FIG. 2;
[0019] FIG. 4 is a side view of a co-extrusion machine and a press
roller forming a multi-layer electrode according to the teachings
of the present disclosure;
[0020] FIG. 5A is a side cross-sectional view of the multi-layer
electrode in FIG. 4 according to one variation of the present
disclosure;
[0021] FIG. 5B is a side cross-sectional view of the multi-layer
electrode in in FIG. 4 according to another variation of the
present disclosure; and
[0022] FIG. 6 is a flow chart of a method of forming a multi-layer
electrode for a capacitive pressure sensor according to the
teachings of the present disclosure.
[0023] The drawings described herein are for illustration purposes
only and are not intended to limit the scope of the present
disclosure in any way.
DETAILED DESCRIPTION
[0024] The following description is merely exemplary in nature and
is not intended to limit the present disclosure, application, or
uses. It should be understood that throughout the drawings,
corresponding reference numerals indicate like or corresponding
parts and features.
[0025] Referring to FIG. 1, a step for manufacturing a multi-layer
electrode for a capacitive pressure sensor using a printer 10 is
shown. The printer 10 includes a first roller 100, a second roller
110 and an ink container 120 with an electrically conductive ink
122 (referred to herein simply as "conductive ink"). In some
variations of the present disclosure, the printer 10 is a
rotogravure printer 10, the first roller 100 is an impression
roller 100, and the second roller 110 is a plate cylinder 110 with
a plate 112 having cells 114. As shown in FIG. 1, the plate
cylinder 110 rotates such that the cells 114 pass through and are
filled with the conductive ink 122, and then come into contact with
a print surface 142 of a polymer film (layer) 140 moving between
the impression roller 100 and the plate 112 such that the
conductive ink 122 is transferred to the print surface 142. In at
least one variation, a wiper 124 (also known as a doctor blade) is
included and removes excess conductive ink 122 from the plate 112
and the cells 114 before the cells 114 reach the polymer layer
140.
[0026] In some variations, the polymer layer 140 is provided from a
feed roller 130 and then gathered or rolled onto a take-up roller
150. That is, in some variations the printer 10 is a roll to roll
printer. In addition, the conductive ink 122 dries and forms a
plurality of conductive ink layers 122a on the polymer layer 140
before and/or during being rolled onto the take-up roller 150. The
sections or areas of the polymer layer 140 with the conductive ink
layers 122a form a plurality of mutual capacitance sensor layers
160 (FIG. 2) of a multi-layer electrode described in greater detail
below. As used herein, the term or phrase "mutual capacitance
sensor layer" refers to a capacitance sensor layer with a planar
construction such that the electrodes and traces for the sensor
layer are fabricated on the same plane of insulating substrate
material.
[0027] Non-limiting examples of the polymer layer 140 include
polymer layers (e.g., polymer sheet or film) made from polyethylene
(PE), polyethylene terephthalate (PET), polytetrafluoroethylene
(PTFE), and polyvinyl chloride (PVC), polypropylene (PP), polyamide
(PA), among others. In some variations the polymer layer 140 is
made from recycled polymer material(s). Also, in some variations
the polymer layer 140 has a thickness between about 0.25 mm to
about 10 mm, for example between about 0.4 mm to about 7.5 mm, or
between about 0.5 mm to about 6 mm.
[0028] Also, non-limiting examples of conductive ink 122 include
silver inks, nano-silver inks, copper inks, carbon nanotube inks,
carbon/graphene inks, indium tin oxide (ITO) inks, and conductive
polymer inks, among others. In some variations the conductive ink
includes a solvent and/or such as but not limited to ethanol, an
ethyl solvent, methanol, a methyl solvent, among others. And in at
least one variation, the conductive ink layer has a thickness
between about 5 micrometers (.mu.m) and about 100 .mu.m, for
example, between about 5 .mu.m and about 50 .mu.m, between about
7.5 .mu.m and about 30 .mu.m, or between about 10 .mu.m and about
20 .mu.m.
[0029] Referring to FIGS. 3A-3B, in some variations the conductive
ink layer 122a is disposed directly onto the polymer layer 140 to
form a mutual capacitance sensor layer 160a as shown in FIG. 3A,
while in other variations at least one additional layer 125
(referred to hereafter simply as "additional layer 125") is
disposed between the conductive ink layer 122a and the polymer
layer 140 as shown in FIG. 3B. For example, in some variations the
polymer layer 140 is a transparent or translucent polymer layer and
the additional layer 125 is one or more decorative layers (e.g., an
additional ink layer(s)) such that an image or color is visible
through the polymer layer 140 (e.g., when viewing from the -z
direction).
[0030] Referring to FIG. 4, another step for manufacturing the
multi-layer electrode is shown where a co-extrusion machine 20 with
a first extruder 210 and a second extruder 220 is used to form a
co-extruded layer 170 with a conductive polymer layer 172 (FIGS.
5A-5B) and a dielectric layer 174. In some variations, the first
extruder 210 is configured to extrude the conductive polymer layer
172 (FIGS. 5A-5B) and the second extruder 220 is configured to
extrude the dielectric layer 174. In other variations, the first
extruder 210 is configured to extrude dielectric layer 174 and the
second extruder 220 configured to extrude the conductive polymer
layer 172. And in some variations, the dielectric layer 174 is a
foam dielectric layer.
[0031] As shown in FIG. 4, the first extruder 210 extrudes material
for the conductive polymer layer 172 and the second extruder 220
extrudes material for the dielectric layer 174 to a multi-manifold
230 and through a T-die 240 to form the co-extruded layer 170. It
should be understood that the extrusion temperature or range of
extrusion temperatures for the conductive polymer layer 172 and the
dielectric layer 174 will vary and be a function of material
supplier recommendations and/or melting temperature of the
material. In addition the extrusion temperature can vary throughout
the various zones of the first extruder 210 and the second extruder
220. For example, in one non-limiting example the first extruder
210 and the second extruder 220 (referred to herein collectively as
"extruders 210, 220") each have a rear zone (not shown) where
material is dropped into the extruders 210, 220, one or more middle
zones (not shown) where material is melted and mixes, a front zone
(not shown) where temperature of the melted material is stabilized,
and an extension and die (not shown) where the co-extruded layer
170 is formed. For example, for materials such as ethylene-vinyl
acetate (EVA) with a desired melting temperature of 205.degree. F.
(96.degree. C.), an extruder or co-extruder could have a rear zone
with a desired temperature of 90.degree. F. (32.degree. C.), a
first middle zone with a desired temperature of 150.degree. F.
(66.degree. C.), a second middle zone with a desired temperature of
205.degree. F. (96.degree. C.), and a front zone, extension and die
with a desired temperature of 205.degree. F. (96.degree. C.). And
for materials such as polyethylene terephthalate (PET) with a
desired melting temperature of 482.degree. F. (250.degree. C.), an
extruder or co-extruder could have a rear zone with a desired
temperature of 500.degree. F. (260.degree. C.), a first and second
middle zone with a desired temperature of 518.degree. F.
(270.degree. C.), a front zone with a desired temperature of
536.degree. F. (280.degree. C.), and an extension and die with a
desired temperature of 554.degree. F. (290.degree. C.).
[0032] In some variations the conductive polymer layer 172 has a
thickness between about 0.2 mm to about 10.0 mm, for example
between about 0.3 mm to about 6.0 mm, between 0.5 mm to about 2.5
mm, or between about 0.5 mm to about 1.0 mm.
[0033] In some variations the conductive polymer layer 172 includes
one or more fillers. As used herein the term "filler" or "fillers"
refers to particles, nanoparticles, fibers, nanotubes, among others
that provide or enhance a physical, mechanical and/or chemical
property of the conductive polymer layer 172. For example, in some
variations the conductive polymer layer 172 can include a carbon
filler to enhance the electrical and/or mechanical properties of
the conductive polymer layer 172. Particularly, the conductive
polymer layer 172 can include between about 2 weight percent (wt.
%) to about 15 wt. % of graphene. In the alternative, or in
addition to, the conductive polymer layer 172 can include between
about 0.01 wt. % to about 5 wt. % carbon nanotubes. In some
variations, the conductive polymer layer 172 includes between about
8 wt. % to about 10 wt. % graphene and between about 0.01 wt. % to
about 1.0 wt. % carbon nanotubes. One non-limiting example of the
graphene is GrapheneBlack.TM. from Nano-xplore which is low cost
multi-layer graphene (6-10 layers) and one non-limiting example of
the carbon nanotubes is ATHLOS.TM. Carbon Nanostructures (CNS) from
Cabot.
[0034] Accordingly, the conductive polymer layer 172 has desired
and tailored electrical properties. In addition, in some variations
the conductive polymer layer 172 has desired mechanical properties.
For example, in at least one variation the conductive polymer layer
172 has an electrical resistivity less than or equal to 10 Ohms per
cubic millimeter (Ohm/mm.sup.3) and in some variations the
conductive polymer layer 172 has a flexural modulus equal to or
greater than 5,000 megapascals (MPa). In at least one variation the
conductive polymer layer 172 has an electrical resistivity less
than or equal to 10 Ohm/mm.sup.3 and a flexural modulus equal to or
greater than 5,000 MPa.
[0035] In some variations the dielectric layer 174 is a dielectric
foam layer with a thickness between about 0.2 mm to about 15 mm,
for example between about 0.3 mm to about 13 mm, between about 0.4
mm to about 12.5 mm, or between about 0.5 mm to about 12 mm. Also,
non-limiting examples of the dielectric layer 174 include
dielectric layers formed from polyethylene, polyethylene foam,
polyurethane, among others. In some variations, the dielectric
layer 174 is formed from a foamed polymer such as but not limited
to polypropylene (PP) foam, thermoplastic elastomer (TPE) foam,
polyvinyl chloride (PVC) foam, thermoplastic polyurethane (TPU)
foam, thermoplastic vulcanizate (TPV) foam, among others.
[0036] In some variations the co-extruded layer 170 is co-extruded
onto a cooling roller 270. And in such variations the polymer layer
140 with the plurality of mutual capacitance sensor layers 160 on a
supply roller 250 is press rolled onto the co-extruded layer 170
with a press roller 260 such that a plurality of multi-layer
electrodes 180 are formed. In other variations, the first extruder
210 and the second extruder 220 extrude the co-extruder layer 170
onto a separate roller (not shown) for storage and/or additional
processing before being press rolled onto the mutual capacitance
sensor layer 160. In addition, in at least one variation an
adhesive (not shown) is applied between the polymer layer 140 with
the plurality of mutual capacitance sensor layers 160 and the
co-extruded layer 170 before being press rolled together such that
bonding or adhesion between the plurality of mutual capacitance
sensor layers and the co-extruded layer 170 is enhanced.
[0037] It should be understood that the plurality of multi-layer
electrodes 180 (i.e., the co-extruded layer 170 press rolled and
bonded to the polymer layer 140 with the plurality of mutual
capacitance sensor layers 160 bonded thereto) can be rolled onto
another roller (not shown) for storage and/or further processing,
cut into a plurality of sheets (not shown) comprising the plurality
of multi-layer electrodes 180 for storage and/or further
processing, and the like.
[0038] Referring to FIGS. 5A-5B, in some variations the co-extruded
layer 170 is pressed rolled onto the mutual capacitance sensor
layer 160a to form a multi-layer electrode 180a as shown in FIG.
5A, while in other variations the co-extruded layer 170 is pressed
rolled onto the mutual capacitance sensor layer 160b to form a
multi-layer electrode 180b (collectively referred to herein as
"multi-layer electrodes 180") as shown on FIG. 5B. Also, and as
shown in FIGS. 5A-5B, the dielectric layer 174 is rolled onto the
conductive ink layer 122a such that the dielectric layer 174 is
disposed between the conductive ink layer 122a and the conductive
polymer layer 172. Accordingly, the multi-layer electrodes 180 are
configured for use as or to be used as part of a pressure
sensor.
[0039] For example, when the conductive ink layer 122a or the
conductive polymer layer 172 are electrically connected to an
energy source (e.g., a battery) a self-capacitance mode of the
multi-layer electrode 180 is provided. In the alternative, when the
conductive ink layer 122a and the conductive polymer layer 172 are
electrically connected to an energy source a mutual-capacitance
mode of the multi-layer electrode 180 is provided. In some
variations the conductive ink layer 122a is a top or outer layer
and serves as a ground electrode and the conductive polymer layer
172 is a bottom or inner layer and serves as an activated
electrode. In such variations, pressure applied on the polymer
layer 140 results in squeezing of compression of the dielectric
layer 174 such that a capacitive field proportional to the applied
pressure is created. In addition, the flexural modulus of the
conductive polymer layer 172 provides a rigidity or stiffness for
the multi-layer electrodes 180 such that normal or typical pressure
from an individual's hand and fingers applied to the multi-layer
electrodes 180 results in a desired capacitive field.
[0040] Referring to FIG. 6, a method 30 of manufacturing the
multi-layer electrode 180 is shown. The method 30 includes roll to
roll printing a conductive ink layer onto a polymer layer and
forming a mutual capacitance sensor layer at 300, co-extruding a
conductive polymer layer and a dielectric layer and forming a
co-extruded layer at 310, and press rolling the mutual capacitance
sensor layer and the co-extruded layer together to form the
multi-layer electrode at 320. In some variations, an adhesive
(e.g., a spray adhesive) is applied between the mutual capacitance
sensor layer and the co-extruded layer at 315 before press rolling
at 320 such that adhesion between the mutual capacitance sensor
layer and co-extruded layers is enhanced.
[0041] Unless otherwise expressly indicated herein, all numerical
values indicating mechanical/thermal properties, compositional
percentages, dimensions and/or tolerances, or other characteristics
are to be understood as modified by the word "about" or
"approximately" in describing the scope of the present disclosure.
This modification is desired for various reasons including
industrial practice, material, manufacturing, and assembly
tolerances, and testing capability.
[0042] As used herein, the phrase at least one of A, B, and C
should be construed to mean a logical (A OR B OR C), using a
non-exclusive logical OR, and should not be construed to mean "at
least one of A, at least one of B, and at least one of C."
[0043] The description of the disclosure is merely exemplary in
nature and, thus, variations that do not depart from the substance
of the disclosure are intended to be within the scope of the
disclosure. Such variations are not to be regarded as a departure
from the spirit and scope of the disclosure.
* * * * *